/* * Copyright (C) Volition, Inc. 1999. All rights reserved. * * All source code herein is the property of Volition, Inc. You may not sell * or otherwise commercially exploit the source or things you created based on the * source. * */ #include #include #include #include #include "physics/physics.h" #include "freespace2/freespace.h" #include "io/timer.h" // for the damping issue #include "ai/ai_profiles.h" #include "mission/missionparse.h" // defines for physics functions #define MAX_TURN_LIMIT 0.2618f // about 15 degrees #define ROT_DEBUG #define ROTVEL_TOL 0.1 // Amount of rotvel is decreased if over cap #define ROTVEL_CAP 14.0 // Rotational velocity cap for live objects #define DEAD_ROTVEL_CAP 16.3 // Rotational velocity cap for dead objects #define MAX_SHIP_SPEED 500 // Maximum speed allowed after whack or shockwave #define RESET_SHIP_SPEED 440 // Speed that a ship is reset to after exceeding MAX_SHIP_SPEED #define SW_ROT_FACTOR 5 // increase in rotational time constant in shockwave #define SW_BLAST_DURATION 2000 // maximum duration of shockwave #define REDUCED_DAMP_FACTOR 10 // increase in side_slip and acceleration time constants (scaled according to reduced damp time) #define REDUCED_DAMP_VEL 30 // change in velocity at which reduced_damp_time is 2000 ms #define REDUCED_DAMP_TIME 2000 // ms (2.0 sec) #define WEAPON_SHAKE_TIME 500 // ms (0.5 sec) viewer shake time after hit by weapon (implemented via afterburner shake) #define SPECIAL_WARP_T_CONST 0.651 // special warp time constant (loose 99 % of excess speed in 3 sec) #define PHYS_DEBUG // check if (vel > 500) or (displacement in one frame > 350) void update_reduced_damp_timestamp( physics_info *pi, float impulse ); float velocity_ramp (float v_in, float v_goal, float time_const, float t); float glide_ramp (float v_in, float v_goal, float ramp_time_const, float accel_mult); void physics_init( physics_info * pi ) { memset( pi, 0, sizeof(physics_info) ); pi->mass = 10.0f; // This ship weighs 10 units pi->side_slip_time_const = 0.05f; pi->rotdamp = 0.1f; pi->max_vel.xyz.x = 100.0f; //sideways pi->max_vel.xyz.y = 100.0f; //up/down pi->max_vel.xyz.z = 100.0f; //forward pi->max_rear_vel = 100.0f; //backward -- controlled seperately pi->max_rotvel.xyz.x = 2.0f; //pitch pi->max_rotvel.xyz.y = 1.0f; //heading pi->max_rotvel.xyz.z = 2.0f; //bank pi->prev_ramp_vel.xyz.x = 0.0f; pi->prev_ramp_vel.xyz.y = 0.0f; pi->prev_ramp_vel.xyz.z = 0.0f; pi->desired_vel.xyz.x = 0.0f; pi->desired_vel.xyz.y = 0.0f; pi->desired_vel.xyz.z = 0.0f; pi->slide_accel_time_const=pi->side_slip_time_const; // slide using max_vel.xyz.x & .xyz.y pi->slide_decel_time_const=pi->side_slip_time_const; // slide using max_vel.xyz.x & .xyz.y pi->afterburner_decay = 1; pi->forward_thrust = 0.0f; pi->vert_thrust = 0.0f; //added these two in order to get side and forward thrusters pi->side_thrust = 0.0f; //to glow brighter when the ship is moving in the right direction -Bobboau pi->flags = 0; // default values for moment of inertia vm_vec_make( &pi->I_body_inv.vec.rvec, 1e-5f, 0.0f, 0.0f ); vm_vec_make( &pi->I_body_inv.vec.uvec, 0.0f, 1e-5f, 0.0f ); vm_vec_make( &pi->I_body_inv.vec.fvec, 0.0f, 0.0f, 1e-5f ); } //========================================================================== // apply_physics - This does correct physics independent of frame rate. // // Given: // damping = damping factor. Setting this to zero make the object instantly // go to the target velocity. Increasing it makes the object ramp // up or down to the target velocity. // desired_vel = the target velocity // initial_vel = velocity at last call // t = elapsed time since last call // // Returns: // new_vel = current velocity // delta_pos = delta position (framevec) // You can extend this to 3d by calling it 3 times, once for each x,y,z component. void apply_physics( float damping, float desired_vel, float initial_vel, float t, float * new_vel, float * delta_pos ) { if ( damping < 0.0001f ) { if ( delta_pos ) *delta_pos = desired_vel*t; if ( new_vel ) *new_vel = desired_vel; } else { float dv, e; dv = initial_vel - desired_vel; e = (float)exp( -t/damping ); if ( delta_pos ) *delta_pos = (1.0f - e)*dv*damping + desired_vel*t; if ( new_vel ) *new_vel = dv*e + desired_vel; } } float Physics_viewer_bank = 0.0f; int Physics_viewer_direction = PHYSICS_VIEWER_FRONT; static physics_info * Viewer_physics_info = NULL; // If you would like Physics_viewer_bank to be tracked (Which is needed // for rotating 3d bitmaps) call this and pass it a pointer to the // viewer's physics info. void physics_set_viewer( physics_info * p, int dir ) { if ( (Viewer_physics_info != p) || (Physics_viewer_direction != dir) ) { Viewer_physics_info = p; Physics_viewer_bank = 0.0f; Physics_viewer_direction = dir; } } // ----------------------------------------------------------------------------------------------------------- // add rotational velocity & acceleration void physics_sim_rot(matrix * orient, physics_info * pi, float sim_time ) { angles tangles; vec3d new_vel; matrix tmp; float shock_amplitude; float rotdamp; float shock_fraction_time_left; Assert(is_valid_matrix(orient)); Assert(is_valid_vec(&pi->rotvel)); Assert(is_valid_vec(&pi->desired_rotvel)); // Handle special case of shockwave shock_amplitude = 0.0f; if ( pi->flags & PF_IN_SHOCKWAVE ) { if ( timestamp_elapsed(pi->shockwave_decay) ) { pi->flags &= ~PF_IN_SHOCKWAVE; rotdamp = pi->rotdamp; } else { shock_fraction_time_left = timestamp_until( pi->shockwave_decay ) / (float) SW_BLAST_DURATION; rotdamp = pi->rotdamp + pi->rotdamp * (SW_ROT_FACTOR - 1) * shock_fraction_time_left; shock_amplitude = pi->shockwave_shake_amp * shock_fraction_time_left; } } else { rotdamp = pi->rotdamp; } // Do rotational physics with given damping apply_physics( rotdamp, pi->desired_rotvel.xyz.x, pi->rotvel.xyz.x, sim_time, &new_vel.xyz.x, NULL ); apply_physics( rotdamp, pi->desired_rotvel.xyz.y, pi->rotvel.xyz.y, sim_time, &new_vel.xyz.y, NULL ); apply_physics( rotdamp, pi->desired_rotvel.xyz.z, pi->rotvel.xyz.z, sim_time, &new_vel.xyz.z, NULL ); /* #ifdef ROT_DEBUG if (check_rotvel_limit( pi )) { nprintf(("Physics", "rotvel reset in physics_sim_rot\n")); } #endif */ Assert(is_valid_vec(&new_vel)); pi->rotvel = new_vel; tangles.p = pi->rotvel.xyz.x*sim_time; tangles.h = pi->rotvel.xyz.y*sim_time; tangles.b = pi->rotvel.xyz.z*sim_time; // If this is the viewer_object, keep track of the // changes in banking so that rotated bitmaps look correct. // This is used by the g3_draw_rotated_bitmap function. if ( pi == Viewer_physics_info ) { switch(Physics_viewer_direction){ case PHYSICS_VIEWER_FRONT: Physics_viewer_bank -= tangles.b; break; case PHYSICS_VIEWER_UP: Physics_viewer_bank -= tangles.h; break; case PHYSICS_VIEWER_REAR: Physics_viewer_bank += tangles.b; break; case PHYSICS_VIEWER_LEFT: Physics_viewer_bank += tangles.p; break; case PHYSICS_VIEWER_RIGHT: Physics_viewer_bank -= tangles.p; break; default: Physics_viewer_bank -= tangles.b; break; } if ( Physics_viewer_bank < 0.0f ){ Physics_viewer_bank += 2.0f * PI; } if ( Physics_viewer_bank > 2.0f * PI ){ Physics_viewer_bank -= 2.0f * PI; } } /* // Make ship shake due to afterburner. if (pi->flags & PF_AFTERBURNER_ON || !timestamp_elapsed(pi->afterburner_decay) ) { float max_speed; max_speed = vm_vec_mag_quick(&pi->max_vel); tangles.p += (float) (rand()-RAND_MAX_2)/RAND_MAX * pi->speed/max_speed/64.0f; tangles.h += (float) (rand()-RAND_MAX_2)/RAND_MAX * pi->speed/max_speed/64.0f; if ( pi->flags & PF_AFTERBURNER_ON ) { pi->afterburner_decay = timestamp(ABURN_DECAY_TIME); } } */ // Make ship shake due to shockwave, decreasing in amplitude at the end of the shockwave if ( pi->flags & PF_IN_SHOCKWAVE ) { tangles.p += (float) (myrand()-RAND_MAX_2)/RAND_MAX * shock_amplitude; tangles.h += (float) (myrand()-RAND_MAX_2)/RAND_MAX * shock_amplitude; } vm_angles_2_matrix(&pi->last_rotmat, &tangles ); vm_matrix_x_matrix( &tmp, orient, &pi->last_rotmat ); *orient = tmp; vm_orthogonalize_matrix(orient); } // ----------------------------------------------------------------------------------------------------------- // add rotational velocity & acceleration void physics_sim_rot_editor(matrix * orient, physics_info * pi, float sim_time) { angles tangles; vec3d new_vel; matrix tmp; angles t1, t2; apply_physics( pi->rotdamp, pi->desired_rotvel.xyz.x, pi->rotvel.xyz.x, sim_time, &new_vel.xyz.x, NULL ); apply_physics( pi->rotdamp, pi->desired_rotvel.xyz.y, pi->rotvel.xyz.y, sim_time, &new_vel.xyz.y, NULL ); apply_physics( pi->rotdamp, pi->desired_rotvel.xyz.z, pi->rotvel.xyz.z, sim_time, &new_vel.xyz.z, NULL ); pi->rotvel = new_vel; tangles.p = pi->rotvel.xyz.x*sim_time; tangles.h = pi->rotvel.xyz.y*sim_time; tangles.b = pi->rotvel.xyz.z*sim_time; t1 = t2 = tangles; t1.h = 0.0f; t1.b = 0.0f; t2.p = 0.0f; t2.b = 0.0f; // put in p & b like normal vm_angles_2_matrix(&pi->last_rotmat, &t1 ); vm_matrix_x_matrix( &tmp, orient, &pi->last_rotmat ); // Put in heading separately vm_angles_2_matrix(&pi->last_rotmat, &t2 ); vm_matrix_x_matrix( orient, &pi->last_rotmat, &tmp ); vm_orthogonalize_matrix(orient); } // Adds velocity to position // finds velocity and displacement in local coords void physics_sim_vel(vec3d * position, physics_info * pi, float sim_time, matrix *orient) { vec3d local_disp; // displacement in this frame vec3d local_v_in; // velocity in local coords at the start of this frame vec3d local_desired_vel; // desired velocity in local coords vec3d local_v_out; // velocity in local coords following this frame vec3d damp; // Maybe clear the reduced_damp flag. // This fixes the problem of the player getting near-instantaneous acceleration under unknown circumstances. // The larger problem is probably that PF_USE_VEL is getting stuck set. if ((pi->flags & PF_REDUCED_DAMP) && (timestamp_elapsed(pi->reduced_damp_decay))) { pi->flags &= ~PF_REDUCED_DAMP; } // Set up damping constants based on special conditions // ie. shockwave, collision, weapon, dead if (pi->flags & PF_DEAD_DAMP) { // side_slip_time_const is already quite large and now needs to be applied in all directions vm_vec_make( &damp, pi->side_slip_time_const, pi->side_slip_time_const, pi->side_slip_time_const ); } else if (pi->flags & PF_REDUCED_DAMP) { // case of shock, weapon, collide, etc. if ( timestamp_elapsed(pi->reduced_damp_decay) ) { vm_vec_make( &damp, pi->side_slip_time_const, pi->side_slip_time_const, 0.0f ); } else { // damp is multiplied by fraction and not fraction^2, gives better collision separation float reduced_damp_fraction_time_left = timestamp_until( pi->reduced_damp_decay ) / (float) REDUCED_DAMP_TIME; damp.xyz.x = pi->side_slip_time_const * ( 1 + (REDUCED_DAMP_FACTOR-1) * reduced_damp_fraction_time_left ); damp.xyz.y = pi->side_slip_time_const * ( 1 + (REDUCED_DAMP_FACTOR-1) * reduced_damp_fraction_time_left ); damp.xyz.z = pi->side_slip_time_const * reduced_damp_fraction_time_left * REDUCED_DAMP_FACTOR; } } else { // regular damping if (pi->use_newtonian_damp) { vm_vec_make( &damp, pi->side_slip_time_const, pi->side_slip_time_const, pi->side_slip_time_const ); } else { vm_vec_make( &damp, pi->side_slip_time_const, pi->side_slip_time_const, 0.0f ); } } // Note: CANNOT maintain a *local velocity* since a rotation can occur in this frame. // thus the local velocity of in the next frame can be different (this would require rotate to change local vel // and this is not desired // get local components of current velocity vm_vec_rotate (&local_v_in, &pi->vel, orient); // get local components of desired velocity vm_vec_rotate (&local_desired_vel, &pi->desired_vel, orient); // find updated LOCAL velocity and position in the local x direction apply_physics (damp.xyz.x, local_desired_vel.xyz.x, local_v_in.xyz.x, sim_time, &local_v_out.xyz.x, &local_disp.xyz.x); // find updated LOCAL velocity and position in the local y direction apply_physics (damp.xyz.y, local_desired_vel.xyz.y, local_v_in.xyz.y, sim_time, &local_v_out.xyz.y, &local_disp.xyz.y); // find updated LOCAL velocity and position in the local z direction // for player ship, damp should normally be zero, but may be altered in a shockwave // in death, shockwave,etc. we want damping time const large for all 3 axes // warp in test - make excessive speed drop exponentially from max allowed // become (0.01x in 3 sec) int special_warp_in = FALSE; float excess = local_v_in.xyz.z - pi->max_vel.xyz.z; if (excess > 5 && (pi->flags & PF_SPECIAL_WARP_IN)) { special_warp_in = TRUE; float exp_factor = float(exp(-sim_time / SPECIAL_WARP_T_CONST)); local_v_out.xyz.z = pi->max_vel.xyz.z + excess * exp_factor; local_disp.xyz.z = (pi->max_vel.xyz.z * sim_time) + excess * (float(SPECIAL_WARP_T_CONST) * (1.0f - exp_factor)); } else if (pi->flags & PF_SPECIAL_WARP_OUT) { float exp_factor = float(exp(-sim_time / SPECIAL_WARP_T_CONST)); vec3d temp; vm_vec_rotate(&temp, &pi->prev_ramp_vel, orient); float deficeit = temp.xyz.z - local_v_in.xyz.z; local_v_out.xyz.z = local_v_in.xyz.z + deficeit * (1.0f - exp_factor); local_disp.xyz.z = (local_v_in.xyz.z * sim_time) + deficeit * (sim_time - (float(SPECIAL_WARP_T_CONST) * (1.0f - exp_factor))); } else { apply_physics (damp.xyz.z, local_desired_vel.xyz.z, local_v_in.xyz.z, sim_time, &local_v_out.xyz.z, &local_disp.xyz.z); } // maybe turn off special warp in flag if ((pi->flags & PF_SPECIAL_WARP_IN) && (excess < 5)) { pi->flags &= ~(PF_SPECIAL_WARP_IN); } // update world position from local to world coords using orient vec3d world_disp; vm_vec_unrotate (&world_disp, &local_disp, orient); #ifdef PHYS_DEBUG // check for excess velocity or translation // GET DaveA. if ( (Game_mode & GM_IN_MISSION) && (Game_mode & GM_NORMAL) ) { // Assert( (sim_time > 0.5f) || (vm_vec_mag_squared(&pi->vel) < 500*500) ); // Assert( (sim_time > 0.5f) || (vm_vec_mag_squared(&world_disp) < 350*350) ); } #endif vm_vec_add2 (position, &world_disp); // update world velocity vm_vec_unrotate(&pi->vel, &local_v_out, orient); if (special_warp_in) { vm_vec_rotate(&pi->prev_ramp_vel, &pi->vel, orient); } } // ----------------------------------------------------------------------------------------------------------- // Simulate a physics object for this frame void physics_sim(vec3d* position, matrix* orient, physics_info* pi, float sim_time) { // check flag which tells us whether or not to do velocity translation if (pi->flags & PF_CONST_VEL) { vm_vec_scale_add2(position, &pi->vel, sim_time); } else { physics_sim_vel(position, pi, sim_time, orient); physics_sim_rot(orient, pi, sim_time); pi->speed = vm_vec_mag(&pi->vel); // Note, cannot use quick version, causes cumulative error, increasing speed. pi->fspeed = vm_vec_dot(&orient->vec.fvec, &pi->vel); // instead of vector magnitude -- use only forward vector since we are only interested in forward velocity } } // ----------------------------------------------------------------------------------------------------------- // Simulate a physics object for this frame. Used by the editor. The difference between // this function and physics_sim() is that this one uses a heading change to rotate around // the universal Y axis, rather than the local orientation's Y axis. Banking is also ignored. void physics_sim_editor(vec3d *position, matrix * orient, physics_info * pi, float sim_time ) { physics_sim_vel(position, pi, sim_time, orient); physics_sim_rot_editor(orient, pi, sim_time); pi->speed = vm_vec_mag_quick(&pi->vel); pi->fspeed = vm_vec_dot(&orient->vec.fvec, &pi->vel); // instead of vector magnitude -- use only forward vector since we are only interested in forward velocity } // function to predict an object's position given the delta time and an objects physics info void physics_predict_pos(physics_info *pi, float delta_time, vec3d *predicted_pos) { apply_physics( pi->side_slip_time_const, pi->desired_vel.xyz.x, pi->vel.xyz.x, delta_time, NULL, &predicted_pos->xyz.x ); apply_physics( pi->side_slip_time_const, pi->desired_vel.xyz.y, pi->vel.xyz.y, delta_time, NULL, &predicted_pos->xyz.y ); apply_physics( pi->side_slip_time_const, pi->desired_vel.xyz.z, pi->vel.xyz.z, delta_time, NULL, &predicted_pos->xyz.z ); } // function to predict an object's velocity given the parameters void physics_predict_vel(physics_info *pi, float delta_time, vec3d *predicted_vel) { if (pi->flags & PF_CONST_VEL) { predicted_vel = &pi->vel; } else { apply_physics( pi->side_slip_time_const, pi->desired_vel.xyz.x, pi->vel.xyz.x, delta_time, &predicted_vel->xyz.x, NULL ); apply_physics( pi->side_slip_time_const, pi->desired_vel.xyz.y, pi->vel.xyz.y, delta_time, &predicted_vel->xyz.y, NULL ); apply_physics( pi->side_slip_time_const, pi->desired_vel.xyz.z, pi->vel.xyz.z, delta_time, &predicted_vel->xyz.z, NULL ); } } // function to predict position and velocity of an object void physics_predict_pos_and_vel(physics_info *pi, float delta_time, vec3d *predicted_vel, vec3d *predicted_pos) { apply_physics( pi->side_slip_time_const, pi->desired_vel.xyz.x, pi->vel.xyz.x, delta_time, &predicted_vel->xyz.x, &predicted_pos->xyz.x ); apply_physics( pi->side_slip_time_const, pi->desired_vel.xyz.y, pi->vel.xyz.y, delta_time, &predicted_vel->xyz.y, &predicted_pos->xyz.y ); apply_physics( pi->side_slip_time_const, pi->desired_vel.xyz.z, pi->vel.xyz.z, delta_time, &predicted_vel->xyz.z, &predicted_pos->xyz.z ); } // physics_read_flying_controls() // // parmeters: *orient ==> // *pi ==> // *ci ==> // Adam: Uncomment-out this define to enable banking while turning. #define BANK_WHEN_TURN // function looks at the flying controls and the current velocity to determine a goal velocity // function determines velocity in object's reference frame and goal velocity in object's reference frame void physics_read_flying_controls( matrix * orient, physics_info * pi, control_info * ci, float sim_time, vec3d *wash_rot) { vec3d goal_vel; // goal velocity in local coords, *not* accounting for ramping of velcity float ramp_time_const; // time constant for velocity ramping // if ( keyd_pressed[KEY_LSHIFT] ) { // keyd_pressed[KEY_LSHIFT] = 0; // Int3(); // } // apply throttle, unless reverse thrusters are held down if (ci->forward != -1.0f) ci->forward += (ci->forward_cruise_percent / 100.0f); // mprintf(("ci->forward == %7.3f\n", ci->forward)); // give control input to cause rotation in engine wash extern int Wash_on; if ( wash_rot && Wash_on ) { ci->pitch += wash_rot->xyz.x; ci->bank += wash_rot->xyz.z; ci->heading += wash_rot->xyz.y; } if (ci->pitch > 1.0f ) ci->pitch = 1.0f; else if (ci->pitch < -1.0f ) ci->pitch = -1.0f; if (ci->vertical > 1.0f ) ci->vertical = 1.0f; else if (ci->vertical < -1.0f ) ci->vertical = -1.0f; if (ci->heading > 1.0f ) ci->heading = 1.0f; else if (ci->heading < -1.0f ) ci->heading = -1.0f; if (ci->sideways > 1.0f ) ci->sideways = 1.0f; else if (ci->sideways < -1.0f ) ci->sideways = -1.0f; if (ci->bank > 1.0f ) ci->bank = 1.0f; else if (ci->bank < -1.0f ) ci->bank = -1.0f; if ( pi->flags & PF_AFTERBURNER_ON ) ci->forward = 1.0f; if (ci->forward > 1.0f ) ci->forward = 1.0f; else if (ci->forward < -1.0f ) ci->forward = -1.0f; pi->desired_rotvel.xyz.x = ci->pitch * pi->max_rotvel.xyz.x; pi->desired_rotvel.xyz.y = ci->heading * pi->max_rotvel.xyz.y; float delta_bank; #ifdef BANK_WHEN_TURN // To change direction of bank, negate the whole expression. // To increase magnitude of banking, decrease denominator. // Adam: The following statement is all the math for banking while turning. delta_bank = - (ci->heading * pi->max_rotvel.xyz.y) * pi->delta_bank_const; #else delta_bank = 0.0f; #endif pi->desired_rotvel.xyz.z = ci->bank * pi->max_rotvel.xyz.z + delta_bank; pi->forward_thrust = ci->forward; pi->vert_thrust = ci->vertical; //added these two in order to get side and forward thrusters pi->side_thrust = ci->sideways; //to glow brighter when the ship is moving in the right direction -Bobboau if ( pi->flags & PF_AFTERBURNER_ON ) { goal_vel.xyz.x = ci->sideways*pi->afterburner_max_vel.xyz.x; goal_vel.xyz.y = ci->vertical*pi->afterburner_max_vel.xyz.y; goal_vel.xyz.z = ci->forward* pi->afterburner_max_vel.xyz.z; } else if ( pi->flags & PF_BOOSTER_ON ) { goal_vel.xyz.x = ci->sideways*pi->booster_max_vel.xyz.x; goal_vel.xyz.y = ci->vertical*pi->booster_max_vel.xyz.y; goal_vel.xyz.z = ci->forward* pi->booster_max_vel.xyz.z; } else { goal_vel.xyz.x = ci->sideways*pi->max_vel.xyz.x; goal_vel.xyz.y = ci->vertical*pi->max_vel.xyz.y; goal_vel.xyz.z = ci->forward* pi->max_vel.xyz.z; } if ( goal_vel.xyz.z < -pi->max_rear_vel ) goal_vel.xyz.z = -pi->max_rear_vel; if ( pi->flags & PF_ACCELERATES ) { // // Determine *resultant* DESIRED VELOCITY (desired_vel) accounting for RAMPING of velocity // Use LOCAL coordinates // if slide_enabled, ramp velocity for x and y, otherwise set goal (0) // always ramp velocity for z // // If reduced damp in effect, then adjust ramp_velocity and desired_velocity can not change as fast. // Scale according to reduced_damp_time_expansion. float reduced_damp_ramp_time_expansion; if ( pi->flags & PF_REDUCED_DAMP ) { float reduced_damp_fraction_time_left = timestamp_until( pi->reduced_damp_decay ) / (float) REDUCED_DAMP_TIME; reduced_damp_ramp_time_expansion = 1.0f + (REDUCED_DAMP_FACTOR-1) * reduced_damp_fraction_time_left; } else { reduced_damp_ramp_time_expansion = 1.0f; } // if ( !use_descent && (Player_obj->phys_info.forward_accel_time_const < 0.1) && !(Ships[Player_obj->instance].flags & SF_DYING) && (Player_obj->type != OBJ_OBSERVER) ) // Int3(); // Get dave A if (pi->flags & PF_SLIDE_ENABLED) { // determine the local velocity // deterimine whether accelerating or decleration toward goal for x if ( goal_vel.xyz.x > 0.0f ) { if ( goal_vel.xyz.x >= pi->prev_ramp_vel.xyz.x ) ramp_time_const = pi->slide_accel_time_const; else ramp_time_const = pi->slide_decel_time_const; } else if ( goal_vel.xyz.x < 0.0f ) { if ( goal_vel.xyz.x <= pi->prev_ramp_vel.xyz.x ) ramp_time_const = pi->slide_accel_time_const; else ramp_time_const = pi->slide_decel_time_const; } else { ramp_time_const = pi->slide_decel_time_const; } // If reduced damp in effect, then adjust ramp_velocity and desired_velocity can not change as fast if ( pi->flags & PF_REDUCED_DAMP ) { ramp_time_const *= reduced_damp_ramp_time_expansion; } pi->prev_ramp_vel.xyz.x = velocity_ramp(pi->prev_ramp_vel.xyz.x, goal_vel.xyz.x, ramp_time_const, sim_time); // deterimine whether accelerating or decleration toward goal for y if ( goal_vel.xyz.y > 0.0f ) { if ( goal_vel.xyz.y >= pi->prev_ramp_vel.xyz.y ) ramp_time_const = pi->slide_accel_time_const; else ramp_time_const = pi->slide_decel_time_const; } else if ( goal_vel.xyz.y < 0.0f ) { if ( goal_vel.xyz.y <= pi->prev_ramp_vel.xyz.y ) ramp_time_const = pi->slide_accel_time_const; else ramp_time_const = pi->slide_decel_time_const; } else { ramp_time_const = pi->slide_decel_time_const; } // If reduced damp in effect, then adjust ramp_velocity and desired_velocity can not change as fast if ( pi->flags & PF_REDUCED_DAMP ) { ramp_time_const *= reduced_damp_ramp_time_expansion; } pi->prev_ramp_vel.xyz.y = velocity_ramp( pi->prev_ramp_vel.xyz.y, goal_vel.xyz.y, ramp_time_const, sim_time); } else { // slide not enabled pi->prev_ramp_vel.xyz.x = 0.0f; pi->prev_ramp_vel.xyz.y = 0.0f; } // deterimine whether accelerating or decleration toward goal for z if ( goal_vel.xyz.z > 0.0f ) { if ( goal_vel.xyz.z >= pi->prev_ramp_vel.xyz.z ) { if ( pi->flags & PF_AFTERBURNER_ON ) ramp_time_const = pi->afterburner_forward_accel_time_const; else if (pi->flags & PF_BOOSTER_ON) ramp_time_const = pi->booster_forward_accel_time_const; else ramp_time_const = pi->forward_accel_time_const; } else { ramp_time_const = pi->forward_decel_time_const; } } else if ( goal_vel.xyz.z < 0.0f ) { ramp_time_const = pi->forward_decel_time_const; // hmm, maybe a reverse_accel_time_const would be a good idea to implement in the future... } else { ramp_time_const = pi->forward_decel_time_const; } // If reduced damp in effect, then adjust ramp_velocity and desired_velocity can not change as fast if ( pi->flags & PF_REDUCED_DAMP ) { ramp_time_const *= reduced_damp_ramp_time_expansion; } pi->prev_ramp_vel.xyz.z = velocity_ramp( pi->prev_ramp_vel.xyz.z, goal_vel.xyz.z, ramp_time_const, sim_time); // this translates local desired velocities to world velocities if ( pi->flags & PF_GLIDING ) { pi->desired_vel = pi->vel; //SUSHI: A (hopefully better) approach to dealing with accelerations in glide mode //Get *actual* current velocities along each axis and use those instead of ramped velocities vec3d local_vel; vm_vec_rotate(&local_vel, &pi->vel, orient); //Having pi->glide_cap == 0 means we're using a dynamic glide cap float curGlideCap = 0.0f; if (pi->glide_cap == 0.0f) { //For dynamic glide capping, normal flight and afterburner have separate glide caps if (pi->flags & PF_AFTERBURNER_ON) { curGlideCap = pi->afterburner_max_vel.xyz.z; } else { //Take the maximum value in X, Y, and Z (including overclocking) curGlideCap = MAX(MAX(pi->max_vel.xyz.x,pi->max_vel.xyz.y), pi->max_vel.xyz.z); } } else { curGlideCap = pi->glide_cap; } //If we're near the (positive) glide cap, decay velocity where we aren't thrusting //This is a hack, but makes the flight feel a lot smoother //Don't do this if we aren't applying any thrust, we have no glide cap, or the accel multiplier is 0 (no thrust while gliding) float cap_decay_threshold = 0.95f; float cap_decay_amount = 0.2f; if (curGlideCap >= 0.0f && vm_vec_mag(&pi->desired_vel) >= cap_decay_threshold * curGlideCap && vm_vec_mag(&goal_vel) > 0.0f && pi->glide_accel_mult != 0.0f) { if (goal_vel.xyz.x == 0.0f) vm_vec_scale_add2(&pi->desired_vel, &orient->vec.rvec, -cap_decay_amount * local_vel.xyz.x); if (goal_vel.xyz.y == 0.0f) vm_vec_scale_add2(&pi->desired_vel, &orient->vec.uvec, -cap_decay_amount * local_vel.xyz.y); if (goal_vel.xyz.z == 0.0f) vm_vec_scale_add2(&pi->desired_vel, &orient->vec.fvec, -cap_decay_amount * local_vel.xyz.z); } //The glide_ramp function uses (basically) the same math as the velocity ramp so that thruster power is consistent //Only ramp if the glide cap is positive vm_vec_scale_add2(&pi->desired_vel, &orient->vec.rvec, glide_ramp(local_vel.xyz.x, goal_vel.xyz.x, pi->slide_accel_time_const, pi->glide_accel_mult)); vm_vec_scale_add2(&pi->desired_vel, &orient->vec.uvec, glide_ramp(local_vel.xyz.y, goal_vel.xyz.y, pi->slide_accel_time_const, pi->glide_accel_mult)); float zVal = 0.0; if (pi->flags & PF_AFTERBURNER_ON) zVal = glide_ramp(local_vel.xyz.z, goal_vel.xyz.z, pi->afterburner_forward_accel_time_const, pi->glide_accel_mult); else { if (goal_vel.xyz.z >= 0.0f) zVal = glide_ramp(local_vel.xyz.z, goal_vel.xyz.z, pi->forward_accel_time_const, pi->glide_accel_mult); else zVal = glide_ramp(local_vel.xyz.z, goal_vel.xyz.z, pi->forward_decel_time_const, pi->glide_accel_mult); } //Hack for some degree of compatibility if $use newtonian damping is off if (!pi->use_newtonian_damp) { zVal *= 0.05f; } vm_vec_scale_add2(&pi->desired_vel, &orient->vec.fvec, zVal); if ( curGlideCap >= 0.0f ) { // so if negative, don't bother with speed cap float currentmag = vm_vec_mag(&pi->desired_vel); if ( currentmag > curGlideCap ) { vm_vec_scale( &pi->desired_vel, curGlideCap / currentmag ); } } } else { vm_vec_zero(&pi->desired_vel); vm_vec_scale_add2( &pi->desired_vel, &orient->vec.rvec, pi->prev_ramp_vel.xyz.x ); vm_vec_scale_add2( &pi->desired_vel, &orient->vec.uvec, pi->prev_ramp_vel.xyz.y ); vm_vec_scale_add2( &pi->desired_vel, &orient->vec.fvec, pi->prev_ramp_vel.xyz.z ); } } else // object does not accelerate (PF_ACCELERATES not set) pi->desired_vel = pi->vel; } // ---------------------------------------------------------------- // Do *dest = *delta unless: // *delta is pretty small // and they are of different signs. void physics_set_rotvel_and_saturate(float *dest, float delta) { /* if ((delta ^ *dest) < 0) { if (abs(delta) < F1_0/8) { // mprintf((0, "D")); *dest = delta/4; } else // mprintf((0, "d")); *dest = delta; } else { // mprintf((0, "!")); *dest = delta; } */ *dest = delta; } // ---------------------------------------------------------------------------- // physics_apply_whack applies an instaneous whack on an object changing // both the objects velocity and the rotational velocity based on the impulse // being applied. // // input: impulse => impulse vector ( force*time = impulse = change in momentum (mv) ) // pos => vector from center of mass to location of where the force acts // pi => pointer to phys_info struct of object getting whacked // orient => orientation matrix (needed to set rotational impulse in body coords) // mass => mass of the object (may be different from pi.mass if docked) // #define WHACK_LIMIT 0.001f #define ROTVEL_WHACK_CONST 0.12 void physics_apply_whack(vec3d *impulse, vec3d *pos, physics_info *pi, matrix *orient, float mass) { vec3d local_torque, torque; // vec3d npos; // Detect null vector. if ((fl_abs(impulse->xyz.x) <= WHACK_LIMIT) && (fl_abs(impulse->xyz.y) <= WHACK_LIMIT) && (fl_abs(impulse->xyz.z) <= WHACK_LIMIT)) return; // first do the rotational velocity // calculate the torque on the body based on the point on the // object that was hit and the momentum being applied to the object vm_vec_crossprod(&torque, pos, impulse); vm_vec_rotate ( &local_torque, &torque, orient ); vec3d delta_rotvel; vm_vec_rotate( &delta_rotvel, &local_torque, &pi->I_body_inv ); vm_vec_scale ( &delta_rotvel, (float) ROTVEL_WHACK_CONST ); vm_vec_add2( &pi->rotvel, &delta_rotvel ); #ifdef ROT_DEBUG if (check_rotvel_limit( pi )) { nprintf(("Physics", "rotvel reset in physics_apply_whack\n")); } #endif //mprintf(("Whack: %7.3f %7.3f %7.3f\n", pi->rotvel.xyz.x, pi->rotvel.xyz.y, pi->rotvel.xyz.z)); // instant whack on the velocity // reduce damping on all axes pi->flags |= PF_REDUCED_DAMP; update_reduced_damp_timestamp( pi, vm_vec_mag(impulse) ); // find time for shake from weapon to end int dtime = timestamp_until(pi->afterburner_decay); if (dtime < WEAPON_SHAKE_TIME) { pi->afterburner_decay = timestamp( WEAPON_SHAKE_TIME ); } // Goober5000 - pi->mass should probably be just mass, as specified in the header vm_vec_scale_add2( &pi->vel, impulse, 1.0f / mass ); if (!(pi->flags & PF_USE_VEL) && (vm_vec_mag_squared(&pi->vel) > MAX_SHIP_SPEED*MAX_SHIP_SPEED)) { // Get DaveA nprintf(("Physics", "speed reset in physics_apply_whack [speed: %f]\n", vm_vec_mag(&pi->vel))); // Int3(); vm_vec_normalize(&pi->vel); vm_vec_scale(&pi->vel, (float)RESET_SHIP_SPEED); } vm_vec_rotate( &pi->prev_ramp_vel, &pi->vel, orient ); // set so velocity will ramp starting from current speed // ramped velocity is now affected by collision } // function generates a velocity ramp with a given time constant independent of frame rate // uses an exponential approach to desired velocity and a cheat when close to improve closure speed float velocity_ramp (float v_in, float v_goal, float ramp_time_const, float t) { float delta_v; float decay_factor; float dist; // JAS: If no time elapsed, change nothing if ( t==0.0f ) return v_in; delta_v = v_goal - v_in; dist = (float)fl_abs(delta_v); // hack to speed up closure when close to goal if (dist < ramp_time_const/3) ramp_time_const = dist / 3; // Rather than get a divide by zero, just go to the goal if ( ramp_time_const < 0.0001f ) { return v_goal; } // determine decay factor (ranges from 0 for short times to 1 for long times) // when decay factor is near 0, the velocity in nearly unchanged // when decay factor in near 1, the velocity approaches goal decay_factor = (float)exp(- t / ramp_time_const); return (v_in + delta_v * (1.0f - decay_factor) ); } //Handles thrust values when gliding. Purposefully similar to velocity_ramp in order to yeild a similar "feel" in //terms of thruster accels //This is all in the local frame of reference for a single movement axis float glide_ramp (float v_in, float v_goal, float ramp_time_const, float accel_mult) { if (v_goal == 0.0f) { return 0.0f; } //This approach to delta_v allows us to ramp accelerations even in glide mode //Get the difference in velocity between current and goal as thrust //(capped by the goal velocity on one end and 0 on the other) //If accel_mult is < 0, don't ramp (fixed acceleration) float delta_v = 0.0f; if (accel_mult < 0.0f) { if (v_goal > 0.0f) { delta_v = MAX(MIN(v_goal - v_in, v_goal), 0.0f); } else { delta_v = MIN(MAX(v_goal - v_in, v_goal), 0.0f); } } else { delta_v = v_goal * accel_mult; } //Calculate the (decayed) thrust float decay_factor = (ramp_time_const > 0.0f) ? (1.0f - (float)exp(-1 / ramp_time_const)) : 1.0f; return delta_v * decay_factor; } // ---------------------------------------------------------------------------- // physics_apply_shock applies applies a shockwave to an object. This causes a velocity impulse and // and a rotational impulse. This is different than physics_apply_whack since a shock wave is a pressure // wave which acts over the *surface* of the object, not a point. // // inputs: direction_vec => a position vector whose direction is from the center of the shock wave to the object // pressure => the pressure of the shock wave at the object // pi => physics_info structure // orient => matrix orientation of the object // min => vector of minimum values of the bounding box // max => vector of maximum values of the bounding box // radius => bounding box radius of the object, used for scaling rotation // // outputs: makes changes to physics_info structure rotvel and vel variables // #define STD_PRESSURE 1000 // amplitude of standard shockwave blasts #define MIN_RADIUS 10 // radius within which full rotvel and shake applied #define MAX_RADIUS 50 // radius at which no rotvel or shake applied #define MAX_ROTVEL 0.4 // max rotational velocity #define MAX_SHAKE 0.1 // max rotational amplitude of shake #define MAX_VEL 8 // max vel from shockwave void physics_apply_shock(vec3d *direction_vec, float pressure, physics_info *pi, matrix *orient, vec3d *min, vec3d *max, float radius) { vec3d normal; vec3d local_torque, temp_torque, torque; vec3d impact_vec; vec3d area; vec3d sin; if (radius > MAX_RADIUS) { return; } vm_vec_normalize_safe ( direction_vec ); area.xyz.x = (max->xyz.y - min->xyz.z) * (max->xyz.z - min->xyz.z); area.xyz.y = (max->xyz.x - min->xyz.x) * (max->xyz.z - min->xyz.z); area.xyz.z = (max->xyz.x - min->xyz.x) * (max->xyz.y - min->xyz.y); normal.xyz.x = vm_vec_dotprod( direction_vec, &orient->vec.rvec ); normal.xyz.y = vm_vec_dotprod( direction_vec, &orient->vec.uvec ); normal.xyz.z = vm_vec_dotprod( direction_vec, &orient->vec.fvec ); sin.xyz.x = fl_sqrt( fl_abs(1.0f - normal.xyz.x*normal.xyz.x) ); sin.xyz.y = fl_sqrt( fl_abs(1.0f - normal.xyz.y*normal.xyz.y) ); sin.xyz.z = fl_sqrt( fl_abs(1.0f - normal.xyz.z*normal.xyz.z) ); vm_vec_make( &torque, 0.0f, 0.0f, 0.0f ); // find the torque exerted due to the shockwave hitting each face // model the effect of the shockwave as if the shockwave were a plane of projectiles, // all moving in the direction direction_vec. then find the torque as the cross prod // of the force (pressure * area * normal * sin * scale * mass) // normal takes account the fraction of the surface exposed to the shockwave // the sin term is not technically needed but "feels" better // scale factors out the increase in area with larger objects // more massive objects get less rotation // find torque due to forces on the right/left face if ( normal.xyz.x < 0.0f ) // normal < 0, hits the right face vm_vec_copy_scale( &impact_vec, &orient->vec.rvec, max->xyz.x * pressure * area.xyz.x * normal.xyz.x * sin.xyz.x / pi->mass ); else // normal > 0, hits the left face vm_vec_copy_scale( &impact_vec, &orient->vec.rvec, min->xyz.x * pressure * area.xyz.x * -normal.xyz.x * sin.xyz.x / pi->mass ); vm_vec_crossprod( &temp_torque, &impact_vec, direction_vec ); vm_vec_add2( &torque, &temp_torque ); // find torque due to forces on the up/down face if ( normal.xyz.y < 0.0f ) vm_vec_copy_scale( &impact_vec, &orient->vec.uvec, max->xyz.y * pressure * area.xyz.y * normal.xyz.y * sin.xyz.y / pi->mass ); else vm_vec_copy_scale( &impact_vec, &orient->vec.uvec, min->xyz.y * pressure * area.xyz.y * -normal.xyz.y * sin.xyz.y / pi->mass ); vm_vec_crossprod( &temp_torque, &impact_vec, direction_vec ); vm_vec_add2( &torque, &temp_torque ); // find torque due to forces on the forward/backward face if ( normal.xyz.z < 0.0f ) vm_vec_copy_scale( &impact_vec, &orient->vec.fvec, max->xyz.z * pressure * area.xyz.z * normal.xyz.z * sin.xyz.z / pi->mass ); else vm_vec_copy_scale( &impact_vec, &orient->vec.fvec, min->xyz.z * pressure * area.xyz.z * -normal.xyz.z * sin.xyz.z / pi->mass ); vm_vec_crossprod( &temp_torque, &impact_vec, direction_vec ); vm_vec_add2( &torque, &temp_torque ); // compute delta rotvel, scale according to blast and radius float scale; vec3d delta_rotvel; vm_vec_rotate( &local_torque, &torque, orient ); vm_vec_copy_normalize(&delta_rotvel, &local_torque); if (radius < MIN_RADIUS) { scale = 1.0f; } else { scale = (MAX_RADIUS - radius)/(MAX_RADIUS-MIN_RADIUS); } vm_vec_scale(&delta_rotvel, (float)(MAX_ROTVEL*(pressure/STD_PRESSURE)*scale)); // nprintf(("Physics", "rotvel scale %f\n", (MAX_ROTVEL*(pressure/STD_PRESSURE)*scale))); vm_vec_add2(&pi->rotvel, &delta_rotvel); // set shockwave shake amplitude, duration, flag pi->shockwave_shake_amp = (float)(MAX_SHAKE*(pressure/STD_PRESSURE)*scale); pi->shockwave_decay = timestamp( SW_BLAST_DURATION ); pi->flags |= PF_IN_SHOCKWAVE; // set reduced translational damping, set flags float velocity_scale = (float)MAX_VEL*scale; pi->flags |= PF_REDUCED_DAMP; update_reduced_damp_timestamp( pi, velocity_scale*pi->mass ); vm_vec_scale_add2( &pi->vel, direction_vec, velocity_scale ); vm_vec_rotate(&pi->prev_ramp_vel, &pi->vel, orient); // set so velocity will ramp starting from current speed // check that kick from shockwave is not too large if (!(pi->flags & PF_USE_VEL) && (vm_vec_mag_squared(&pi->vel) > MAX_SHIP_SPEED*MAX_SHIP_SPEED)) { // Get DaveA nprintf(("Physics", "speed reset in physics_apply_shock [speed: %f]\n", vm_vec_mag(&pi->vel))); // Int3(); vm_vec_normalize(&pi->vel); vm_vec_scale(&pi->vel, (float)RESET_SHIP_SPEED); } #ifdef ROT_DEBUG if (check_rotvel_limit( pi )) { nprintf(("Physics", "rotvel reset in physics_apply_shock\n")); } #endif // ramped velocity is now affected by collision } // ---------------------------------------------------------------------------- // physics_collide_whack applies an instaneous whack on an object changing // both the objects velocity and the rotational velocity based on the impulse // being applied. // // input: impulse => impulse vector ( force*time = impulse = change in momentum (mv) ) // world_delta_rotvel => change in rotational velocity (already calculated) // pi => pointer to phys_info struct of object getting whacked // orient => orientation matrix (needed to set rotational impulse in body coords) // // Warning: Do not change ROTVEL_COLLIDE_WHACK_CONST. This will mess up collision physics. // If you need to change the rotation, change COLLISION_ROTATION_FACTOR in collide_ship_ship. #define ROTVEL_COLLIDE_WHACK_CONST 1.0 void physics_collide_whack( vec3d *impulse, vec3d *world_delta_rotvel, physics_info *pi, matrix *orient ) { vec3d body_delta_rotvel; // Detect null vector. if ((fl_abs(impulse->xyz.x) <= WHACK_LIMIT) && (fl_abs(impulse->xyz.y) <= WHACK_LIMIT) && (fl_abs(impulse->xyz.z) <= WHACK_LIMIT)) return; vm_vec_rotate( &body_delta_rotvel, world_delta_rotvel, orient ); // vm_vec_scale( &body_delta_rotvel, (float) ROTVEL_COLLIDE_WHACK_CONST ); vm_vec_add2( &pi->rotvel, &body_delta_rotvel ); #ifdef ROT_DEBUG if (check_rotvel_limit( pi )) { nprintf(("Physics", "rotvel reset in physics_collide_whack\n")); } #endif update_reduced_damp_timestamp( pi, vm_vec_mag(impulse) ); // find time for shake from weapon to end int dtime = timestamp_until(pi->afterburner_decay); if (dtime < WEAPON_SHAKE_TIME) { pi->afterburner_decay = timestamp( WEAPON_SHAKE_TIME ); } pi->flags |= PF_REDUCED_DAMP; vm_vec_scale_add2( &pi->vel, impulse, 1.0f / pi->mass ); // check that collision does not give ship too much speed // reset if too high if (!(pi->flags & PF_USE_VEL) && (vm_vec_mag_squared(&pi->vel) > MAX_SHIP_SPEED*MAX_SHIP_SPEED)) { // Get DaveA nprintf(("Physics", "speed reset in physics_collide_whack [speed: %f]\n", vm_vec_mag(&pi->vel))); // Int3(); vm_vec_normalize(&pi->vel); vm_vec_scale(&pi->vel, (float)RESET_SHIP_SPEED); } vm_vec_rotate( &pi->prev_ramp_vel, &pi->vel, orient ); // set so velocity will ramp starting from current speed // ramped velocity is now affected by collision // rotate previous ramp velocity (in model coord) to be same as vel (in world coords) } int check_rotvel_limit( physics_info *pi ) { if ( 0 == pi->flags ) // weapon return 0; if ( Fred_running ) return 0; int change_made = 0; if ( !(pi->flags & PF_DEAD_DAMP) ) { // case of normal, live ship // -- Commented out by MK: Assert( vm_vec_mag_squared(&pi->max_rotvel) > ROTVEL_TOL ); // Assert( (pi->max_rotvel.xyz.x <= ROTVEL_CAP) && (pi->max_rotvel.xyz.y <= ROTVEL_CAP) && (pi->max_rotvel.xyz.z <= ROTVEL_CAP) ); // Warning(LOCATION,"Excessive rotvel (wx: %f, wy: %f, wz:%f)\n", pi->rotvel.xyz.x, pi->rotvel.xyz.y, pi->rotvel.xyz.z); if ( fl_abs(pi->rotvel.xyz.x) > pi->max_rotvel.xyz.x ) { pi->rotvel.xyz.x = (pi->rotvel.xyz.x / fl_abs(pi->rotvel.xyz.x)) * (pi->max_rotvel.xyz.x - (float) ROTVEL_TOL); change_made = 1; } if ( fl_abs(pi->rotvel.xyz.y) > pi->max_rotvel.xyz.y ) { pi->rotvel.xyz.y = (pi->rotvel.xyz.y / fl_abs(pi->rotvel.xyz.y)) * (pi->max_rotvel.xyz.y - (float) ROTVEL_TOL); change_made = 1; } if ( fl_abs(pi->rotvel.xyz.z) > pi->max_rotvel.xyz.z ) { pi->rotvel.xyz.z = (pi->rotvel.xyz.z / fl_abs(pi->rotvel.xyz.z)) * (pi->max_rotvel.xyz.z - (float) ROTVEL_TOL); change_made = 1; } } else { // case of dead ship if ( fl_abs(pi->rotvel.xyz.x) > DEAD_ROTVEL_CAP ) { pi->rotvel.xyz.x = (pi->rotvel.xyz.x / fl_abs(pi->rotvel.xyz.x)) * (float) (DEAD_ROTVEL_CAP - ROTVEL_TOL); change_made = 1; } if ( fl_abs(pi->rotvel.xyz.y) > DEAD_ROTVEL_CAP ) { pi->rotvel.xyz.y = (pi->rotvel.xyz.y / fl_abs(pi->rotvel.xyz.y)) * (float) (DEAD_ROTVEL_CAP - ROTVEL_TOL); change_made = 1; } if ( fl_abs(pi->rotvel.xyz.z) > DEAD_ROTVEL_CAP ) { pi->rotvel.xyz.z = (pi->rotvel.xyz.z / fl_abs(pi->rotvel.xyz.z)) * (float) (DEAD_ROTVEL_CAP - ROTVEL_TOL); change_made = 1; } } return change_made; } // ---------------------------------------------------------------------------- // update_reduced_damp_timestamp() // void update_reduced_damp_timestamp( physics_info *pi, float impulse ) { // Compute duration of reduced damp from present // Compare with current value and increase if greater, otherwise ignore int reduced_damp_decay_time; reduced_damp_decay_time = (int) (REDUCED_DAMP_TIME * impulse / (REDUCED_DAMP_VEL * pi->mass)); if ( reduced_damp_decay_time > REDUCED_DAMP_TIME ) reduced_damp_decay_time = REDUCED_DAMP_TIME; // Reset timestamp if larger than current (if any) if ( timestamp_valid( pi->reduced_damp_decay ) ) { int time_left = timestamp_until( pi->reduced_damp_decay ); if ( time_left > 0 ) { // increment old time, but apply cap int new_time = reduced_damp_decay_time + time_left; if ( new_time < REDUCED_DAMP_TIME ) { pi->reduced_damp_decay = timestamp( new_time ); } } else { pi->reduced_damp_decay = timestamp( reduced_damp_decay_time ); } } else { // set if not valid pi->reduced_damp_decay = timestamp( reduced_damp_decay_time ); } } //*************************CLASS: avd_movement************************* avd_movement::avd_movement() { clear(); } void avd_movement::clear() { memset(this, 0, sizeof(avd_movement)); } void avd_movement::get(float Time, float *Position, float *Velocity) { this->update(Time); if(Position != NULL) *Position = Pc; if(Velocity != NULL) *Velocity = Vc; } void avd_movement::get(float *Position, float *Velocity) { float time = (float)(timestamp() - TSi)/1000.0f; this->get(time, Position, Velocity); } void avd_movement::set(float position) { this->clear(); Pi = Pf = Pc = position; } void avd_movement::setAVD(float final_position, float total_movement_time, float starting_accleration_time, float ending_acceleration_time, float final_velocity) { //Make sure Pc et al are up-to-date this->update(); Pf = final_position; Tf = total_movement_time; Tai = starting_accleration_time; Taf = ending_acceleration_time; Vf = final_velocity; if(Tai+Taf >= Tf) { Tai = Tf; Taf = 0.0f; } if(Tf <= 0.0f) { Pc = Pi = Pf; Vc = Vi = Vf; return; } Pi = Pc; Vi = Vc; TSi = timestamp(); Vm = (Pf-Pi-0.5f*(Vi*Tai)-0.5f*(Vf*Taf)) / (Tf - 0.5f*Tai - 0.5f*Taf); Ai = (Vm-Vi)/Tai; Af = (Vf-Vm)/Taf; } void avd_movement::setVD(float total_movement_time, float ending_acceleration_time, float final_velocity) { //Make sure Pc et al are up-to-date this->update(); Tf = total_movement_time; Tai = 0.0f; Taf = ending_acceleration_time; Vf = final_velocity; Pi = Pc; Vm = Vi = Vc; TSi = timestamp(); Ai = 0.0f; Af = (Vf-Vm)/Taf; Pf = Pi + Pf*(Tf - Taf) + Vm*Taf + 0.5f*Af*(Taf*Taf); } void avd_movement::update() { float time = (float)(timestamp() - TSi)/1000.0f; this->update(time); } void avd_movement::update(float Time) { if(Tf <= 0.0f) { //This avd_movement is just serving as static storage Pc = Pi; Vc = Vi; } else if(Time >= Tf) { //Movement has ended, but the thing may still have a constant velocity Pc = Pf + Vf*(Time-Tf); Vc = Vf; } else { //Movement is in-progress and we must calculate where the thing is now. float t = Time; float Tc = 0.0f; if(t >= 0.0f) { Pc = Pi; Vc = Vi; } if(t >= 0.0f && Tai > 0.0f) { if(t < Tai) Tc = t; else Tc = Tai; Pc = Pc + Vi*Tc + 0.5f*Ai*(Tc*Tc); Vc = Vc + Ai*Tc; } if(t >= Tai && (Tai+Taf) < Tf) { if(t < (Tf-Taf)) Tc = (t-Tai); else Tc = (Tf-Tai-Taf); Pc = Pc + Vm*Tc; Vc = Vc; } if(t >= (Tf-Taf) && Taf > 0.0f) { if(t < Tf) Tc = t-(Tf-Taf); else Tc = Taf; Pc = Pc + Vm*Tc + 0.5f*Af*(Tc*Tc); Vc = Vc + Af*Tc; } } }